Spas, including hot tubs and the like, that contain heated water can use a substantial amount of power. Whether electric or gas, the thermal energy required to achieve and maintain an optimum temperature can be considerable. The typical spa cover is fabricated from an expanded polystyrene core encased in a water-impervious vinyl sheath. The problem with this design, is that within a remarkably short time the expanded polystyrene core becomes impregnated with water, typically from condensing vapors from the heated water in the spa. The thermal insulating properties of the spa cover diminish and the power required to maintain temperature in the spa water dramatically increases.
Many of the deficiencies in conventional hinged spa covers that utilize a crossbar lift mechanism in which the two segments of the hinged cover are folded over a support tube, have been eliminated by the thermally efficient designs found in my patents cited above and incorporated herein by reference. These designs eliminate the chimney effect for thermal losses between the folding segments of the spa cover, which are spaced apart at the hinge to accommodate the crossbar. However, the gradual degradation of the insulating properties of the expanded polystyrene (EPS) as it absorbs water becomes a significant factor in the thermal efficiency of the spa system.
In addition to maintaining a flat line thermal efficiency, the present designs eliminate the use of 14 cubic feet of EPS foam and the annoyance of a spa cover gradually becoming heavier and more of a chore to remove and replace, thereby lessening the enjoyment of the spa system.